Antinociceptive and anti-inflammatory activities of the Jatropha isabellei dichloromethane fraction and isolation and quantitative determination of jatrophone by UFLC-DAD

Context: Jatropha isabellei Müll. Arg. (Euphorbiaceae) has been used in the traditional medicine to treat arthritis. Objective: To evaluate the anti-inflammatory and antinociceptive activities of the dichloromethane fraction (DFJi) from underground parts of J. isabellei, and to develop an analytical method to quantify the diterpene jatrophone. Materials and methods: Anti-inflammatory and antinociceptive activities of the DFji were determined by an acute arthritis model through assessment of the paw elevation time (PET) and articular diameter (AD) of Wistar rats treated orally (50, 100 or 200 mg/kg in a single-dose), and intravenously (0.1, 1, 10, 25 or 50 mg/kg in a bolus administration). The isolation of jatrophone from the DFji was carried out and confirmed by spectroscopic techniques. A UFLC-DAD method was developed and validated. Results: When orally administered, the highest dose (200 mg/kg) of DFJi was able to significantly reduce the PET to 24.8 ± 1.4 s (p < 0.01), when compared with the control group (33.7 ± 1.8 s). The administration of the intravenous dose of 10 mg/kg reduced the PET to 14.8 ± 0.3 s (p < 0.001). The oral and intravenous administration of the DFJi at dose of 200 and 10 mg/kg significantly prevented the formation of edema, reducing the AD in 25.3% and 32.5% (p < 0.01), respectively. The UFLC-DAD method allowed the quantification of jatrophone, which was found to be around 90 μg/mg of fraction. Discussion and conclusion: The DFJi displayed antinociceptive and antiedematogenic activities, representing a promising plant product for the arthritis treatment